Method for manufacturing solid polymer electrolyte/electrode composites, battery produced using the method and method for producing the same

ABSTRACT

Disclosed are a method for manufacturing a solid polymer electrolyte film/electrode composite, in which a porous electrode made from an electochemically active substance is used as an electrode and the pressure inside the porous electrode is reduced in order to fix the solid polymer electrolyte (SPE) film or pre-solid polymer electrolyte (pre-SPE) film to the porous electrode, a battery obtained by impregnating the electrode in the solid polymer electrolyte film/electrode composite with an electrolytic solution under reduced pressure and a method for producing such. The invention provides a thin, uniform film-shaped solid polymer electrolyte/electrode composite with ease. The battery fabricated with the composite is free of defects such as short, has high performance and, hence, is useful.

BACKGROUND ART

[0001] The present invention relates to a method for manufacturing acomposites of a solid polymer electrolyte and an electrode, and alsorelates to a battery produced using the manufacturing method and to amethod for producing a battery using the manufacturing method.

DESCRIPTION OF THE RELATED ART

[0002] A solid polymer electrolyte (hereinafter sometimes abbreviated as“SPE”) is a polymer substance containing an electrolyte salt whichpolymer substance exhibits high ionic conductivity in the solid stateand development thereof is being driven for the purpose of theapplication to various sensors, fuel batteries, coming generationbatteries, photoelectric cells and electrochromic elements.

[0003] In order to impart high ionic conductivity to SPE, lower glasstransition temperatures are more advantageous. However, if such is thecase, the film strength is reduced and the SPE film disadvantageouslybecomes difficult to handle industrially. While there has been proposeda method of adding an organic solvent to SPE, this incurs a reduction inthe strength thereof and the handling of the SPE film becomes even moredifficult.

[0004] Accordingly, in order to laminate SPE on an electrode, a methodof coating an SPE prepolymer directly on the electrode surface and thencuring the polymer by cross-linking might be considered promising.However, the coating method is disadvantageous in that the thickness ofSPE layer is difficult to control and homogeneous thin films can behardly obtained.

[0005] To cope with this, a method of forming SPE into a film andadhering the film to an electrode is being attempted.

[0006] However, this method has problems in that the SPE film isgenerally weak in the strength and difficult to adhere to the electrodewithout any breakage. Moreover, SPE film containing an electrolyticsolution is highly hygroscopic and can be difficultly adhered to theelectrode while maintaining its low water content.

SUMMARY OF THE INVENTION

[0007] Under these circumstances, the present invention has been madeand the objects of the present invention are to provide a method formanufacturing a composite of a solid polymer electrolyte and anelectrode which allows for fixation of a film comprising an SPE film ora film made from an SPE polymer containing no electrolyte (hereafter,abbreviated as pre-SPE) (in the present invention, the term “solidpolymer electrolyte film” includes the both films above) to an electrodein a simple and easy manner and to provide a battery produced using sucha manufacturing method and a method for producing a battery using themethod.

[0008] As a result of extensive investigations, the present inventorshave found that the above-described objects can be attained by fixing asolid polymer electrolyte film to a porous electrode while reducing thepressure inside the porous electrode, fabricating a battery, and thenimpregnating the electrode in a solution comprising an electrolyte salthaving high hygroscopic property. The present invention has beenaccomplished based on these findings.

[0009] By the method for manufacturing a composite of a solid polymerelectrolyte film and an electrode according to the present invention,there can easily be obtained a thin composite having a uniform thicknessand the solid battery obtained with this composite is free of short orthe like, has high performance and is useful.

[0010] That is, the present invention provides a method formanufacturing a solid polymer electrolyte film/electrode composite, themethod comprising fixing a solid polymer electrolyte film to a porouselectrode comprising an electrochemical active substance while reducingthe pressure inside the porous electrode.

[0011] Also, the present invention provides a method for producing abattery, the method comprising impregnating the electrode of the solidpolymer electrolyte film/electrode composite obtained by the methoddescribed above with an electrolytic solution under reduced pressure anda battery obtained by the method.

[0012] That is, the present invention relates to the method formanufacturing a solid polymer electrolyte film/electrode composites, tothe method for producing a battery using the composites and to a batteryproduced by the production method as follows.

[0013] 1) A method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode, comprising the stepsof: providing a thin film-shaped porous electrode comprising anelectrochemically active substance; and reducing the pressure inside theporous electrode.

[0014] 2) A method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode, comprising the stepsof: coating on an electrode surface of the thin film-shaped porouselectrode a polymerizable compound which is converted to a solid polymerelectrolyte or a pre-solid polymer electrolyte upon polymerization; andreducing the pressure inside the porous electrode after superposing theelectrode surface coated with the polymerizable compound onto the solidpolymer electrolyte film.

[0015] 3) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode as described in 1) or2) above, wherein the solid polymer electrolyte film has an ionconductivity at room temperature of 10⁻⁵ S/cm or more.

[0016] 4) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode as described in anyone of 1) to 3) above, wherein the solid polymer electrolyte filmcontains a cross-linking polymer having a urethane bond and anoxyalkylene group.

[0017] 5) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode as described in 2)above, wherein the polymerizable compound coated on the electrode has aurethane bond and an oxyalkylene group.

[0018] 6) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode as described in anyone of 1) to 5) above, wherein the solid polymer electrolyte film isobtained by polymerizing a composition comprising a solvent havingdissolved therein a polymerizable compound.

[0019] 7) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode as described in anyone of 1) to 5) above, wherein the solid polymer electrolyte film isobtained by polymerizing a composition comprising a solvent containingan electrolyte salt having dissolved therein a polymerizable compound.

[0020] 8) A method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode, comprising the stepsof: coating a polymerizable compound which converts to a solid polymerelectrolyte or a pre-solid polymer electrolyte upon polymerization on anelectrode surface of a laminate film comprising a film base material anda film-shaped porous electrode on the film base material; reducing thepressure inside the electrode after superposing the surface coated withthe polymerizable compound onto the solid polymer electrolyte film; andpeeling off the film base material.

[0021] 9) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode, as described in 8)above, further comprising the step of polymerizing the polymerizablecompound after the step of reducing the pressure inside the electrode.

[0022] 10) The method for manufacturing a composite of a solid polymerelectrolyte film and a thin film-shaped electrode, as described in 8) or9) above, wherein the film base material has a metal or metal oxidecoating, on which the film-shaped porous electrode is provided to form alaminate film.

[0023] 11) A method for producing a battery, comprising the step of:providing a composite of a solid polymer electrolyte film and anelectrode obtained by the method as described in any one of 1) to 10)above; and impregnating under reduced pressure the electrode in thecomposite with an electrolytic solution.

[0024] 12) The method for producing a battery as described in 11) above,wherein the electrolytic solution comprises a polymerizable compound andan electrolyte salt and the polymerizable compound is polymerized tocure after the impregnation under reduced pressure.

[0025] 13) A method for producing a battery, comprising the step of:providing a composite of a solid polymer electrolyte film containing noelectrolyte salt and an electrode as described in 6) above; andimpregnating the electrode of the composite with an electrolyticsolution under reduced pressure.

[0026] 14) The method for producing a battery as described in 13) above,wherein the electrolytic solution comprises a polymerizable compound andan electrolyte salt and the polymerizable compound is polymerized tocure after the impregnation under reduced pressure.

[0027] 15) A method for producing a battery, comprising the step of:providing a composite of a solid polymer electrolyte film containing anelectrolyte salt and an electrode as described in 7) above; andimpregnating the electrode of the composite with an electrolyticsolution which has a concentration of an electrolyte salt greater than aconcentration at which the electrolytic solution has a maximum ionconductivity.

[0028] 16) The method for producing a battery as described in 15) above,wherein the electrolytic solution comprises a polymerizable compound andan electrolyte salt and the polymerizable compound is polymerized tocure after the impregnation under reduced pressure.

[0029] 17) A battery obtained by the method as described in any one of11) to 16) above.

DETAILED DESCRIPTION

[0030] The porous electrode used in the present invention comprises anelectrochemical active substance. Specific examples of theelectrochemical active substance include metal oxides such as cobaltoxide, manganese oxide, vanadium oxide, nickel oxide and molybdenumoxide, metal sulfides such as molybdenum sulfide, titanium sulfide andvanadium sulfide, electrically conductive polymers such as polyaniline,polyacetylene and derivatives thereof, polyparaphenylene and aderivative thereof, polypyrrole and a derivative thereof, andpolythienylene and a derivative thereof, and carbon materials such asnatural graphite, artificial graphite, vapor phase processed graphite,petroleum coke, coal coke, graphite fluoride, pitch-base carbon andpolyacene.

[0031] The SPE film or pre-SPE film used in the present invention isobtained by polymerizing a polymerizable compound-containing solutioncomposition which contains a polymerizable compound and at least asolvent.

[0032] In the present invention, the polymerizable compound-containingsolution composition for the SPE film which can be used includes amixture of a solvent containing an electrolyte and a polymerizablecompound, and preferably used is a polymerizable compound-containingsolution composition for the pre-SPE that comprises a mixture of asolution containing no electrolyte and a polymerizable compound. This isbecause while the former provides a composite of a solid polymerelectrolyte film and electrode only by polymerizing and fixing the filmto the electrode, there occurs a problem due to the hygroscopic propertyof the electrolyte. In the case of the latter, the composite of apre-SPE film and an electrode is fabricated and then the composite isimpregnated with an electrolytic solution to give a composite of a solidpolymer electrolyte film and electrode. This, however, causes no suchproblem and, hence, is advantageous.

[0033] The polymerization reaction of the polymerizablecompound-containing solution composition can be performed using activelight beams such as visible light, ultraviolet ray, electron beam, γ rayand X ray, as well as the thermal polymerization. The polymerizablecompound includes a functional monomer or oligomer having at least onehetero atom. Specific examples thereof include (meth)acrylic esters anddi(meth)acrylic esters each having an oxyalkylene chain, such asω-methyloligooxyethyl methacrylate; alkyl(meth)acrylates such as methylmethacrylate and n-butyl acrylate; (meth)acrylamide-base compounds suchas acrylamide, methacrylamide, N,N-dimethylacrylamide,N,N-dimethylmethacrylamide, acryloylmorpholine, methacryloylmorpholineand N,N-dimethylaminopropyl (meth) acrylamide; N-vinylamide-basecompounds such as N-vinylacetamide and N-vinylformamide; alkyl vinylethers such as ethyl vinyl ether; polyfunctional (meth)acrylates such astrimethylolpropane (meth)acrylate, pentaerythritol penta(meth)acrylateand dipentaerythritol hexa (meth) acrylate; and various urethaneacrylate prepolymers such as phenylglycidyl ether acrylate hexamethylenediisocyanate urethane prepolymer, phenylglycidyl ether acrylateisophorone diisocyanate urethane prepolymer.

[0034] Further, a polymerizable compound which has polymerizablefunctional groups comprising a urethane bond and an oxyalkylene group,represented by the following formula can be used.

CH₂=C (R¹)CO [O(CH₂)_(x)(CH(CH₃))_(y)]_(z)NHCOO—R²—

[0035] wherein R¹ represents hydrogen or an alkyl group, R² represents adivalent organic group containing an oxyalkylene group, which may have alinear, branched or cyclic structure and may contain an atom other thancarbon, hydrogen and oxygen, X and Y each independently represents 0 oran integer of from 1 to 5, and Z represents 0 or an integer of from 1 to10, provided that when X is 0 and Y is 0, Z is 0; (CH₂) and (CH(CH₃))may be irregularly disposed; and R¹, R², the values of X, Y and Z in oneunit may be independent from those in another unit within one moleculeand do not have to be the same among units.

[0036] Specific examples of the compound represented by the formulaabove include ω-methyloligooxyethyl N-methacryloylcarbamate andω-methyloligooxyethyl methacryloyloxyethylcarbamate. These polymerizablecompounds may be used individually or in combination of two or morethereof.

[0037] Among the above-described polymerizable compounds, the compoundshaving an urethane bond and an oxyalkylene group are preferred, andexamples thereof include oxyalkylene chain-containing urethane(meth)acrylate, urethane acrylate, oxyalkylene chain-containing(meth)acrylic ester and (meth)acrylamide-base compounds, withoxyalkylene chain-containing urethane (meth)acrylate being morepreferred.

[0038] In order to obtain a cross-linked form of the polymer, at leastone polyfunctional polymerizable compound can be used in combination asa copolymer component. Examples of the cross-linking polyfunctionalcompound which can be copolymerized include a diacrylate ordimethacrylate of polyalkylene glycol having a molecular weight of 1,000or less (e.g., oligoethylene oxide, polyethylene oxide, oligopropyleneoxide, polypropylene oxide), a diacrylate or dimethacrylate of linear,branched or cyclic alkylene glycol having from 2 to 20 carbon atoms(e.g., ethylene glycol, propylene glycol, trimethylene glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol,1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, cyclohexane-1,4-diol),a polyfunctional acrylate or methacrylate compound resulting fromdisplacing two or more OH groups of a linear, branched or cyclicpolyhydric alcohol having 3 or more OH groups (e.g., glycerin,trimethylolpropane, pentaerythritol, sorbitol, glucose, mannitol), withan acryloyloxy group or a methacryloyloxy group, such astrimethylolpropane triacrylate (TMPTA), trimethylolpropanetrimethacrylate (TMPTM), pentaerythritol triacrylate (PETA),pentaerythritol trimethacrylate (PETM), dipentaerythritol hexaacrylate(DPHA) and dipentaerythritol hexamethacrylate (DPHM), a polyfunctionalacrylate compound having a molecular weight of 2,000 or less resultingfrom displacing two or more OH groups of the above-described polyhydricalcohol with an acryloyloxy-oligo (or poly) ethyleneoxy (orpropyleneoxy) group, a polyfunctional methacrylate compound having amolecular weight of 2,000 or less resulting from displacing two or moreOH groups of the above-described polyhydric alcohol with amethacryloyloxy-oligo (or poly) ethyleneoxy (or propyleneoxy) group, anaromatic urethane acrylate (or methacrylate) compound such as reactionproduct of tolylene diisocyanate with hydroxyalkyl acrylate (ormethacrylate) (e.g., hydroxyethyl acrylate), an aliphatic urethaneacrylate (or methacrylate) compound such as reaction product of analiphatic diisocyanate (e.g., hexamethylene diisocyanate) withhydroxyalkyl acrylate (methacrylate) (e.g., hydroxyethyl methacrylate),a divinyl compound such as divinylbenzene, divinyl ether anddivinylsulfone, and a diallyl compound such as diallyl phthalate anddiallyl carbonate.

[0039] The SPE for use in the present invention usually has an ionconductivity of 10⁻⁵ S/cm or more, preferably from 5×10⁻⁵ to 10⁻¹ S/cm.

[0040] Examples of the electrolyte salt include LiClO₄, LiBF₄, LiAsF₆,LiCF₃SO₃, LiPF₆, LiN (CF₃SO₃)₂, LiI, LiBr, LISCN, NaI, Li₂B₁₀Cl₁₀LiCF₃CO₂, NaBr, NaSCN, KSCN, MgCl₂, Mg(ClO₄)₂, (CH₃)₄NBF₄, (CH₃)₄NBr,(C₂H₅)₄NClO₄, (C₂H₅)₄NI, (C₃H₇)₄NBr, (n-C ₄H₉)₄NClO₄, (n—C₄H₉)₄NI and(n-C₅H₁₁) ₄NI. Among these, a Li salt such as LiBF₄, LiClO₄ and LiPF₆,and a quaternary ammonium salt such as (C₂H₅)₄NClO₄ are preferred. Theratio of the electrolyte salt blended is generally from 0.1 to 70 partsby weight, preferably from 1 to 50 parts by weight, more preferably from1 to 30 parts by weight, per 100 parts by weight of the polymerizablecompound.

[0041] The solvent for the polymerizable compound-containing solutioncomposition for use in the present invention include tetrahydrofuran,2-methyltetrahydrofuran, 1,3-dioxolane, 4,4-dimethyl-1,3-dioxane,γ-butyrolactone, diethyl carbonate, dimethyl carbonate, methyl ethylcarbonate, ethylene carbonate, propylene carbonate, butylene carbonate,sulfolane, 3-methylsulfolane, t-butyl ether, i-butyl ether,1,2-dimethoxyethane, 1,2-diethoxymethoxyethane, methyldiglyme,methyltriglyme, methyltetraglyme, ethylglyme and ethyldiglyme. These maybe used individually or in combination of two or more thereof.

[0042] To the polymerizable compound-containing solution composition maybe added a polymerization initiator. Examples of the polymerizationinitiator include a radical thermal polymerization initiator such asazobisisobutyronitrile and benzoyl peroxide, a radicalphotopolymerization initiator such as benzyl methyl ketal andbenzophenone, a cation polymerization catalyst such as a protonic acid(e.g., CF₃COOH) and a Lewis acid (e.g., BF₃, AlCl₃), and an anionpolymerization catalyst such as butyl lithium, sodium naphthalene andlithium alkoxide.

[0043] In the present invention, there can be used a laminate film whichcomprises a base material and a film form porous electrode providedthereon. After a SPE film or pre-SPE film is fixed to the electrodesurface of the laminate film, the base material is peeled off in thefinal step to fabricate an SPE/electrode composite.

[0044] The film base material used herein is not particularly limitedand examples thereof include polyolefins such as polyethylene andpolypropylene, and general thermoplastic resins such as polyvinylchloride, polyester and polyamide. The film may be either non-stretchedor stretched. The film base material generally has a thickness of from 1to 5,000 μm, preferably from 1 to 1,000 μm, more preferably from 5 to100 The laminate film for use in the present invention is obtained bylaminating the above-described SPE or pre-SPE film on a film basematerial. The SPE is laminated by a known coating method such as adoctor knife method and then polymerized to cure by thermalpolymerization or the like. Use of a thin film such as a metal or metaloxide formed as by vapor deposition on the surface of the film basematerial is preferred in view of wettability and peelability. The SPEfilm of the laminate film usually has a thickness of from 1 to 1,000 μm,preferably from 1 to 300 μm, more preferably from 1 to 50 μm.

[0045] The method for manufacturing a solid polymer electrolytefilm/electrode composite according to the present invention is featuredby superposing a surface of SPE film or pre-SPE film of the laminatefilm onto a surface of the porous electrode and then reducing thepressure inside the porous electrode for fixation. The pressure isreduced, for example, by a method such that a porous electrode is placedon a gas permeable material such as sintered metal and the other surfaceside of the gas permeable material is decompressed by means of a vacuumpump.

[0046] The battery of the present invention is obtained by impregnatingthe solid polymer electrolyte film/electrode composite fabricatedaccording to the above-described method with an electrolytic solutionunder reduced pressure.

[0047] As the electrolytic solution can be used a solution obtained bydissolving an electrolyte salt in a solvent. If desired, a solutioncontaining the above-described polymerizable compound and polymerizationinitiator as well as the electrolyte salt may be used so that theelectrolytic solution after the impregnation can be cured by the methoddescribed above such as thermal polymerization.

[0048] Taking account of the diffusion of the electrolyte salt into theSPE film layer or the pre-SPE film layer upon impregnation of the solidpolymer electrolyte film with the electrolytic solution, theconcentration is preferably set higher than the electrolyteconcentration necessary for giving a maximum ion conductivity (ingeneral, about 1 mol/l).

BEST MODE FOR CARRYING OUT THE INVENTION

[0049] The present invention is described in greater detail below byreferring to examples. However, the present invention is not limited tothe following examples.

EXAMPLE 1

[0050] To 100 parts by weight of Mixture A containing 33 wt % of apolymerizable compound shown below as a pre-SPE polymerizablecompound-containing solution composition:

[0051] (wherein m is 25, is hydrogen:methyl group 7:3 by mol) and 67 wt% of a solvent (a mixture of 75 wt % of ethylene carbonate and 25 wt %of propylene carbonate), 0.25 part by weight of a polymerizationinitiator (a mixture of 50% by weight of 1-hydroxycyclohexyl phenylketone and 50% by weight of benzophenone (trade name: Irgacure 500,produced by Ciba Geigy) was added to prepare a mixed solution.

[0052] A 12 μm-thick polyester film having evaporated alumina on onesurface thereof was used as the film base material and the solutioncomposition prepared above was coated on the alumina evaporated surfaceof the base material by means of a coater to have a thickness of 30 μm.Thereafter, ultraviolet rays were irradiated on the mixed solutioncomposition thus coated to cure the solution composition bycross-linking, thereby obtaining a pre-SPE laminated film. A 30 μm-thickoriented polypropylene (OPP) film was superposed thereon to prepare athree-layer film.

[0053] An electrode having a size slightly smaller than the film basematerial and obtained by coating a mixture of natural graphite polymerwith a binder of 3 wt % polyvinylidene fluoride (PVDF) on a 15 μm-thickcopper foil to have a thickness of 85 μm was used as the negativeelectrode. The electrode was placed on a 2 mm-thick stainless steel-madesintered plate, the surface from which the OPP film of the three-layerfilm had been removed was superposed thereon, and the back surface ofthe sintered plate was decompressed by means of a vacuum pump. Theadhesion of the pre-SPE film to the electrode was confirmed and then,the polyester film was peeled off while continuing the decompression tofix only the pre-SPE film onto the electrode.

[0054] A positive electrode obtained by coating lithium cobalt (LiCoO₂)powder on a 25 μm-thick aluminum foil to have a thickness of 100 μm wassuperposed on the pre-SPE film described above in the same manner asabove to fabricate a battery.

[0055] The battery thus fabricated was dipped in a solution obtained byadding 500 ppm of a thermal polymerization initiator(bis(4-t-butylcyclohexyl) peroxycarbonate, Perloyl TCP produced byNippon Oils and Fats KK) to Mixed Solution B which was prepared bymixing a solvent (diethyl carbonate:ethylene carbonate=1:1) containing10 parts by weight of LiClO₄ as an electrolyte salt per 100 parts byweight of the solvent, with the polymerizable compound prepared above ata mixing ratio of 6:1, and then impregnated therewith under reducedpressure by means of a vacuum pump. Thereafter, the battery impregnatedwas subjected to thermal polymerization at a temperature of 80° C. for30 minutes to cure, thereby manufacturing a solid battery.

[0056] The battery (size: 2 cm×2 cm) obtained was charged and dischargedrepeatedly 10 times under conditions such that the working voltage wasfrom 2.5 to 4.2 V and the electric current was 0.2 mA/cm². As a result,the maximum discharge capacity was 9.8 mAh.

[0057] Further, the battery was charged and discharged repeatedly 10times at an electric current of 2 mA/cm² and then, the maximum dischargecapacity was 8.9 mAh.

EXAMPLE 2

[0058] In the same manner as in Example 1 were prepared a three-layerfilm composed of a polyester film base material and a pre-SPE layer andan OPP layer laminated on the film base material and an electrodecomposed of a copper foil-graphite negative electrode and having a sizeslightly smaller than the film base material.

[0059] The electrode was placed on a stainless steel-made sintered platewhile the OPP film was removed from the three-layer film. On an exposedSPE surface was coated Mixture A of Example 1 to a thickness of 5 μm.Then, the both members were superposed one on another so that thesurface coated with Mixture A contacted the negative electrode surface.Then, the back surface of the sintered plate was decompressed using avacuum pump. After confirming the adhesion of the pre-SPE film to theelectrode, the resulting laminate was irradiated with ultraviolet raysfrom above the polyester film to cure Mixture A to completely adhere thepre-SPE film to the electrode. Subsequently, the polyester film wasremoved while continuing the decompressing, and only the pre-SPE filmwas fixed on the electrode.

[0060] On the electrode/pre-SPE composite thus obtained was superposed apositive electrode having the same structure as that in Example 1 andimpregnated with the same polymerizable electrolytic solution as used inExample 1, followed by thermal polymerization for fixation to fabricatea solid battery.

[0061] The battery thus obtained was charged and discharged in the samemanner as in Example 1 and then, the maximum discharge capacities were9.5 mAh and 8.6 mAh, respectively.

EXAMPLE 3

[0062] A battery was manufactured in the same manner as in Example 1except for using a mixed solution obtained by adding 10 parts by weightof LiClO₄ and 0.25 part by weight of Irgacure 500 to 100 parts by weightof Mixture A. The battery obtained was charged and discharged in thesame manner as in Example 1 and then, the maximum discharge capacitieswere 9.9 mAh and 9.0 mAh, respectively.

COMPARATIVE EXAMPLE 1

[0063] In Example 2, decompression was not performed. As a result, theadhesive strength between the SPE layer and the electrode was weak andthe SPE could not be adhered onto the electrode.

COMPARATIVE EXAMPLE 2

[0064] In Example 2, the electrolyte was coated to have a thickness of30 μm and the decompression was not performed. As a result, on peelingoff the polyester film, the negative electrode was readily peeled offtogether from the copper foil and adhering was difficultly achieved. Abattery barely succeeded in the adhering was evaluated on theperformance and then found to have inferior capability such that themaximum discharge capacities were 9.4 mAh and 4.8 mAh, respectively.

What is claimed is:
 1. A method for manufacturing a composite of a solidpolymer electrolyte film and a thin film-shaped electrode, comprisingthe steps of: providing a thin film-shaped porous electrode comprisingan electrochemically active substance; and reducing the pressure insidethe porous electrode.
 2. A method for manufacturing a composite of asolid polymer electrolyte film and a thin film-shaped electrode,comprising the steps of: coating on an electrode surface of said thinfilm-shaped porous electrode a polymerizable compound which is convertedto a solid polymer electrolyte or a pre-solid polymer electrolyte uponpolymerization; and reducing the pressure inside the porous electrodeafter superposing the electrode surface coated with the polymerizablecompound onto said solid polymer electrolyte film.
 3. The method formanufacturing a composite of a solid polymer electrolyte film and a thinfilm-shaped electrode as claimed in claim 1 or 2 , wherein said solidpolymer electrolyte film has an ion conductivity at room temperature of10⁻⁵ S/cm or more.
 4. The method for manufacturing a composite of asolid polymer electrolyte film and a thin film-shaped electrode asclaimed in any one of claims 1 to 3 , wherein said solid polymerelectrolyte film contains a cross-linking polymer having a urethane bondand an oxyalkylene group.
 5. The method for manufacturing a composite ofa solid polymer electrolyte film and a thin film-shaped electrode asclaimed in claim 2 , wherein said polymerizable compound coated on theelectrode has a urethane bond and an oxyalkylene group.
 6. The methodfor manufacturing a composite of a solid polymer electrolyte film and athin film-shaped electrode as claimed in any one of claims 1 to 5 ,wherein said solid polymer electrolyte film is obtained by polymerizinga composition comprising a solvent having dissolved therein apolymerizable compound.
 7. The method for manufacturing a composite of asolid polymer electrolyte film and a thin film-shaped electrode asclaimed in any one of claims 1 to 5 , wherein said solid polymerelectrolyte film is obtained by polymerizing a composition comprising asolvent containing an electrolyte salt having dissolved therein apolymerizable compound.
 8. A method for manufacturing a composite of asolid polymer electrolyte film and a thin film-shaped electrode,comprising the steps of: coating a polymerizable compound which convertsto a solid polymer electrolyte or a pre-solid polymer electrolyte uponpolymerization on an electrode surface of a laminate film comprising afilm base material and a film-shaped porous electrode on the film basematerial; reducing the pressure inside the electrode after superposingthe surface coated with the polymerizable compound onto said solidpolymer electrolyte film; and peeling off said film base material. 9.The method for manufacturing a composite of a solid polymer electrolytefilm and a thin film-shaped electrode, as claimed in claim 8 , furthercomprising the step of polymerizing the polymerizable compound after thestep of reducing the pressure inside the electrode.
 10. The method formanufacturing a composite of a solid polymer electrolyte film and a thinfilm-shaped electrode, as claimed in claim 8 or 9 , wherein the filmbase material has a metal or metal oxide coating, on which saidfilm-shaped porous electrode is provided to form a laminate film.
 11. Amethod for producing a battery, comprising the step of: providing acomposite of a solid polymer electrolyte film and an electrode obtainedby the method as claimed in any one of claims 1 to 10 ; and impregnatingunder reduced pressure the electrode in said composite with anelectrolytic solution.
 12. The method for producing a battery as claimedin claim 11 , wherein the electrolytic solution comprises apolymerizable compound and an electrolyte salt and the polymerizablecompound is polymerized to cure after the impregnation under reducedpressure.
 13. A method for producing a battery, comprising the step of:providing a composite of a solid polymer electrolyte film containing noelectrolyte salt and an electrode as claimed in claim 6 ; andimpregnating the electrode of said composite with an electrolyticsolution under reduced pressure.
 14. The method for producing a batteryas claimed in claim 13 , wherein the electrolytic solution comprises apolymerizable compound and an electrolyte salt and the polymerizablecompound is polymerized to cure after the impregnation under reducedpressure.
 15. A method for producing a battery, comprising the step of:providing a composite of a solid polymer electrolyte film containing anelectrolyte salt and an electrode as claimed in claim 7 ; andimpregnating the electrode of said composite with an electrolyticsolution which has a concentration of an electrolyte salt greater than aconcentration at which the electrolytic solution has a maximum ionconductivity.
 16. The method for producing a battery as claimed in claim15 , wherein the electrolytic solution comprises a polymerizablecompound and an electrolyte salt and the polymerizable compound ispolymerized to cure after the impregnation under reduced pressure.
 17. Abattery obtained by the method as claimed in any one of claims 11 to 16.